LnRNA-C1orf在七氟烷引起的神经发育毒性中的机制研究

General anesthesia is required for patients undergoing repeated or prolonged non obstetric surgery during pregnancy. Earlier studies have found that sevoflurane affects the development of fetal nervous system and impaired the learning and memory. Based on our previous research, we found that sevoflurane indued the abnormal differentiation of triploblastic of embryos of mice in the first trimester of pregnancy. The water maze showed that the memory ability of their offspring was impaired. Then we used embryonic stem cells to differentiate into neural differentiation as a model to systematically study the mechanism of sevoflurane induced neurodevelopmental toxicity. We found that sevoflurane caused oxidative stress in embryonic stem cells. In this state, the self-renewal ability of embryonic stem cells is reduced, and subsequent neural differentiation is inhibited. Based on this, we proposed the human embryonic stem cells and to induce neuronal differentiation in vitro and using conditional knockdown or overexpression of LncRNA-C1orf transgenic mice in vivo to study the underlying mechanism of sevoflurane induced neurotoxicity when early pregnancy women undergoing nonobstetric surgery in clinical. The mechanism is probably sevoflurane reduced by LncRNA-C1orf, which as the competition of endogenous RNA miRNA-29b, and makes more miRNA-29b target on the downstream gene of the sirt1, leads to self-renewal ability of embryonic stem cells inhibition under oxidative stress, thereby reducing the neuroectodermal differentiation, reduce the final neurons leads to learning and memory impairment.

孕期患者接受反复多次或长时间非产科手术时，需要全身麻醉。有研究发现临床常用全麻药七氟烷可能影响胎儿后续神经系统发育及学习记忆能力。我们前期研究基础发现七氟烷处理后的孕早期孕鼠其胚胎出现三胚层分化异常和子代记忆损伤。随后我们使用胚胎干细胞向神经细胞分化的技术，系统性研究七氟烷的神经发育毒性机制。我们进一步的研究发现七氟烷导致胚胎干细胞产生氧化应激，在这种状态下，胚胎干细胞自我更新能力降低，后续神经分化受到抑制。基于此，我们提出通过体外七氟烷处理人胚胎干细胞后并诱导其向神经元分化，同时体内使用条件性敲低或过表达C1orf转基因小鼠来研究七氟烷是否下调了C1orf，后者作为miRNA-29b的竞争性内源RNA，从而使miRNA-29b作用于其下游基因sirt1，导致胚胎干细胞在七氟烷引起的氧化应激状态下自我更新能力降低，进而向神经外胚层分化减少，最终神经元产生减少，导致了学习记忆损伤。

孕早期妇女接受非产科手术全身麻醉时，吸入麻醉药七氟烷对胎儿后续神经系统发育的影响一直是孕妇和医生关注的焦点。我们使用荧光定量PCR发现七氟烷处理后的孕早期孕鼠其子代记忆能力受到损害，为此，我们拟通过七氟烷处理胚胎干细胞后并诱导其向神经元分化，系统性研究临床孕早期妇女接受非产科手术全身麻醉时，七氟烷对神经发育过程的毒性以及LncRNA-C1orf（Riken）在吸入全麻药物七氟烷引起的神经发育毒性中的作用机制。我们的研究发现:.1、七氟烷通过抑制miRNA-101a的竞争性内源RNA LncRNA-C1orf（Riken），从而使miRNA-101a升高并作用于其下游基因MKP-1，最终导致了神经氧化应激状态增高，神经炎症产生，引起了神经发育毒性。.2、在使用胚胎干细胞向神经元分化的体外模型中，静脉全麻药物氯胺酮引起胚胎干细胞自我更新能力降低，后续向内胚层和中胚层分化增多而向神经外胚层分化减少，进而导致了神经元产生减少，其机制是氯胺酮能够降低神经分化过程中的神经营养因子BDNF的表达，进而影响了神经分化，从而导致神经发育毒性。 .综上所述，我们的研究为孕早期妇女接受非产科手术时降低麻醉对胎儿发育的影响提供理论基础。